there were other similar products that had cocaine in them.
All they did to extract cocaine from the coca leaves was make a tea with distilled spirits, such as vodka. Then you have your extract in the alcohol solution. Perhaps if you heat it all up, you could extract even more and also evaporate some of the alcohol away as well.
Making a tea in water is one of the most basic forms of extracting phytochemicals. You can use water for everything, but it cannot achieve the extraction levels that alcohol does. It may take a larger volume of water to extract the same amount of tea as you would with alcohol.
I would start labeling the tea as a drug if anything beyond water is used for the extraction. To get sugar out of corn, they use acidic liquids. The acids can be used in smaller quantities than water. When consumed, you absorb a larger quantity of the phytochemical than you would with using water. If you take drugs, you want to consume extra amounts of water to make up for the high concentration of drugs.